How to get lower unit/gear box back on??

DirtyDicks

Recruit
Joined
Jun 24, 2002
Messages
5
I have an 82 mercruiser IO and I replaced the impeller. But putting the bottom back on is a b!tch! What is the secret to lining it all up?
 

Trent

Captain
Joined
Nov 17, 2001
Messages
3,333
Re: How to get lower unit/gear box back on??

REMOVAL AND REPLACEMENT OF OUTDRIVES ON MERCRUISER #1 AND ALPHA GEN I<br /><br />REMOVAL OF OUTDRIVE<br /><br />1) Start with outdrive down and control box in forward gear.<br /><br />2) Remove the nuts holding the rearward trim & tilt cylinder anchor pin, save parts.<br /><br />3) Pull the trim & tilt cylinder heads off of the rear pin, save parts.<br /><br />4) Remove the six 5/8 locking nuts & washers from the outdrive at the bell housing, save parts.<br /><br />5) Bump the unit downward or lift & drop it lightly to break the seal between the drive and bell housing.<br /><br />6) Pull rearward on the unit and it should fall into your arms. (Be careful, they are heavy. We suggest two people for this step.)<br /><br />7) Clean surfaces of drive and bell housing.<br /><br />If you encounter problems in pulling off the drive in step 6 above. <br /><br />If it wouldn't come off, there are several tricks to remove it. They are listed below in order of difficulty.<br /><br />1) Try a piece of wood or metal across the two ears at the bottom of the ring, lift and drop the unit on it. <br /><br />2) Try a piece of wood or metal between the cap front and ring, then lift the unit up to hit it. <br /><br />3) Last resort, jam a piece of wood between cap and ring, put the rams back on and trim up. <br /><br />All of the above steps help push the unit outward and off. If the problem is that the gimbal bearing has become stuck on the shaft, (a common problem) the bearing might still be there when the unit comes free <br /><br />REPLACEMENT OF OUTDRIVE<br /><br />1) After checking gimbal bearing and bellows for leaks, install new outdrive mounting set. <br /><br />2) Use a recommended sealant / glue on the large square 'O' ring to the shoulder in the bell. <br /><br />3) Use a recommended sealant / glue in the water passage in the groove on the bell.<br /><br />4) Replace the "O" rings on the shaft of the drive. <br /><br />5) Use a recommended sealant on the outdrive gasket and place it over the studs of the bell. <br /><br />Unless you have an outdrive mounting dolly, two people will be required for the next steps.<br /><br />6) Stand the unit upright and rotate the brass shifter (intermediate shift shaft) clockwise looking down. <br /><br />7) The travel of the shifter should be from 10:00 to 12:00 looking down, 12:00 being straight ahead. <br /><br />8) Roughly speaking, the shifting should be center of boat forward or 12:00, 11:00 neutral, 10:00 reverse. <br /><br />9) The shift box in the boat should still be in forward. <br /><br />10) As you rotate the shifter clockwise, turn the prop counter clock wise until it locks. <br /><br />Never allow the prop to go clockwise or it will rotate the shifter out of position. If this happens go back to 10. <br /><br />On the bell housing of the transom plate is the shift arm with a roller on it. The aluminum slide piece on the cable tip has two arms, which go to the top with the arms inward.<br /><br />11) Place the roller from the shift arm between these two arms. The track below the shift shaft should be facing straight ahead. This is where the top of the brass shifter on the drive slides in upon installation.<br /><br />12) With the drive in forward (step 10) guide the tip of the drive yoke through the gimble bearing. <br /><br />13) Slide the unit forward. As soon as it reaches the shift slide, guide the slide into the square hole on the drive. <br /><br />14) Look in the right side and recheck the shift arm position and roller position (step 11). <br /><br />15) Slide the unit forward until the main shaft hits the coupler spline. It may not go in at this point. <br /><br />16) Keep pressure forward (inward) on the outdrive. Turn the prop counter clockwise, (it will be hard). This will rotate the shaft. Continue this until it slides in, keeping pressure inward as you turn. <br /><br />17) Once the shaft goes into the coupler the unit will no longer turn counter clockwise. Do not force it. <br /><br />18) Bump the unit forward with the palms of your hands until the drive seats, recheck the roller (step 11). <br /><br />19) If the unit resists installation, lift the unit and check that the track on the upper shift is straight and that the brass shifter is going into it smoothly and straight. <br /><br />20) Bump the unit the rest of the way on and replace the nuts and washers. <br /><br />It is good to check the shifting after only two nuts are applied. If removal is required it saves time. <br /><br />21) Replace the trim rams and bushings.
 

Countrybois

Cadet
Joined
Jun 26, 2002
Messages
15
Re: How to get lower unit/gear box back on??

I believe he is trying to reinstall the lower unit, not the outdrive, and it can be pain. Turn the shift mechanism on the lower unit clockwise looking down on it. Try turning the prop clockwise, it should lock. As Trent said, don't let the prop turn counter-clockwise or it will 'shift' out of gear causing your shift coupler to go out of alignment with the shaft on the outdrive. Now raise your lower unit up into the outdrive ensuring that your water tube lines up. If it comes to a stop, either your splined driveshaft isn't aligned properly or your shift linkage is off a little. For the driveshaft, have someone turn the prop clockwise while you apply up pressure to the lower unit. If it's the shift coupler you may need to pull the throttle handle back just a hair to get it to line up. If that is the case make sure after you get it bolted on that the lower unit is shifting properly i.e. shift into forward and check that prop locks if you try to turn it clockwise and ratchets the opposite directions. Shift into reverse and check for the same action just opposite directions. Shift to neutral and check for free spinning both ways.
 

DirtyDicks

Recruit
Joined
Jun 24, 2002
Messages
5
Re: How to get lower unit/gear box back on??

Thanks, I think I got it now. I hope the ****fing part it right. I will test it tomarrow.
 

uglyduck

Recruit
Joined
May 17, 2006
Messages
2
Re: How to get lower unit/gear box back on??

Holy thread revival, hope someone can help me out on this. I'm having some trouble with this exact step.<br /><br />
Originally posted by Countrybois:<br /> Turn the shift mechanism on the lower unit clockwise looking down on it. Try turning the prop clockwise, it should lock.
As I stand at the back of the boat looking down on the bellhousing (outdrive is off). When moving the remote from forward towards neutral/reverse I notice that the upper shift shaft rotates counter clockwise in the bellhousing. Keep this in mind!!<br /><br />I put the remote back in the forward position in preparation to install the outdrive.<br /><br />I put the intermediate shift shaft/coupling in the 12:00 position to line up with the upper shaft which has a channel to accept the intermediate shaft.<br /><br />In order for the intermediate shaft to be in the 12:00 position I turned it counter clockwise until it stopped. I then turned the prop clockwise and it locks.<br /><br />I am now able to seat the outdirve fully onto the bellhousing. WooHoo...wait, not done yet.<br /><br />I get back into the boat and I am unable to pull the shifter back to neutral. It feels like something is hanging up. Remember what I said in the beginning about the upper shaft turning counterclockwise when moving from forward to neutral/reverse (looking from the top). Well, also remember that I set turned the lower shaft counterclockwise all the way. So here it is in forward and need to go to reverse and the lower shaft cannot turn counteclockwise any further. What am I doing wrong here???<br /><br />As a side note, I've taken it off and put it back on 4 times now and am not having any trouble with the shift slide falling out of position. I did however pick up the outdrive from being serviced yesterday. I'm starting to wonder if they didn't set the lower unit in forward before mating the upper and lower. I also checked to be sure that the cable and upper shaft assembly we working by moving the remote with the outdrive off.<br /><br />Sanity check: Could this be some sort of reverse drive?<br /><br />Thank you for any help you can provide.
 

uglyduck

Recruit
Joined
May 17, 2006
Messages
2
Re: How to get lower unit/gear box back on??

If I turn the shift mechanism on the lower shaft clockwise, it locks in the 2:00 position and the shaft coupling does not line up.
 
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